Conventionally automobiles are provided with one or more hydraulic fluid powered systems, e.g. for circulating engine oil for lubrication and cooling, pressurized fluid-operated brakes, and pressurized fluid-operated steering systems. In many instances, each such system is provided with its own pump, which is arranged to be operated from power supplied by the automotive engine. Where a plurality of such pumps is provided, sometimes two or more are powered by the same drive shaft, by being mounted to that shaft or by being arranged to be pulley-driven therefrom.
It is also known to use a single pump to supply pressurized working fluid to a plurality of automotive systems. Such a pump is provided with a reservoir and a switching device. Oil, or equivalent working fluid is pressurized in the reservoir by the pump, and the reservoir outlet means is switchably communicated by the switching device to the fluid power-applying lines communicated to the various fluid power-operated systems. Such a single pump/multiple power-operated system arrangement can be quite complex.